Saw-tooth



UNITED STATES PATENT EErcE.

HENRY WV. WHEELER, OF MOTT, ASSIGNOR OF ONE-HALF TO HENRY L. TATUM AND J. J. BOW'EN, OF SAN FRANCISCO, CALIFORNIA.

SAW-TOOTH.

SPECIFICATION forming part of Letters Patent No. 429,400, dated June 3, 1890.

Application filed December 23, 1889. Serial No. 334,757. (Model) To all whom it may concern:

Be it known that I, HENRY W. WHEELER, a citizen of the-United States, residing at Mott, in the county of Siskiyou and State of California, have invented certain new and useful Improvements in Saw-Teeth; and I do hereby declare that the following is a full, clear, and exact description of the said invention.

This invention relates to improvements in saw-teeth, and more particularly to the class of teeth known as insertible teeth or bits. There are many different styles and patterns of insertible bits in use, all provided with special means for securing them in the sawplate and widely differing from one another in that particular. So far as I am aware, however, these bits, however dissimilar they may be in shape, construction, and attachment, are always provided with a straight transverse cutting-edge, like an ordinary carpenters chisel. The improvements herein described relate to these cutting-edges, and are designed to produce a cutter which can be run with a very much reduced expenditure of driving-power, and which cannot be defiected from a straight course by any condition of the grain of the wood.

There are other advantages incidental to my invention which will be fully pointed out in this specification.

It should be stated in advance that my improvement relates entirely to the cuttingedges of saw-bits, and not to the means of attaching such bits, and they are consequently applicable to all the various styles of sawbits now in use.

In the accompanying drawings, Figure 1 is a perspective view of my improved bit. Fig. 2 is a side elevation of the same. Fig. 3 is a top View of the same, showing also the next succeeding bit. Fig. 4 is a bottom view of the same.

The bit A, of hardened steel, is adapted to fit within a recess in the saw plate or holder, and has one edge curved and grooved to match a corresponding rib on the part to which it is attached. The opposite edge has a curved recess a, and the bit is locked within the recess in the saw-plate or bit-holder by means well known and which need not be particularly described, as they form no part of the present invention.

The cutting-edge d is produced by beveling the end of the bit above and below to an edge, as shown. In the old form of bit this straight cutting-edge is .a straight transverse chisel, somewhat wider than the thickness of the shank of the bit. In my bit, however, by means of an angular bevel c, I produce an obtuse angular cutting and drawing edge d c. This drawing-edge e is produced by beveling the upper side edge of the bit from the point Z. I designate the edge (1 as the breakingedge, because it is on the side where the wood is broken down, and I designate the edge e as the drawing-edge, because it gives a drawing out. The breaking-edge 01 may be at right angles, or nearly so, to the plane of the bit. The drawing-edge may be at any angle to the breaking-edge desired. I have shown it in the drawings at an angle of approximately forty-five degrees.- The breaking-edges are placed alternately on opposite sides of successive teeth, as in Fig. 3.

The practical eifeot of this form of bit in sawing is to give both a direct and a drawing out. Peculiar advantages result from this. In the old form of-bit, having a straight trans verse cutting-edge, the bit breaks the wood down on both sides. The breaking or tearin g of the fiber of the wood is what consumes the greater part of the power required in driving saws. My improved bit breaks the wood down on one side only, cutting it on the other side, and thereby effecting a great saving of power over the old form of cuttingedge. It should be noticed, also, that the entire width of the cutting-edge of the square or horizontal edge tooth must necessarily strike the same formation or same grain of wood in the same way, and often follows the grain and is deflected from a straight line. This occasions waste of lumber and time as well as damage to the saw. My improved tooth cannot be deflected from a straight line, no matter what the formation of the grain of the wood may be, owing to the fact that my tooth cuts the grain horizontally and also at an angle at the same time, and any tendency of the horizontal edge to run with the grain is overcome by the angular cutting-edge. My

improved bit will therefore do equally as good work in green, dried, frozen, or knotted timber. It will also be noticed that inasmuch as my bits cut the wood on one side there is a diminished tendency to loosen the fiber and thereby increase the bulk of'the dust or chip; hence less liability in clogging the saw. Again, the arrangement for my bits is such that the breakingedge of each bit is followed by the cutting-edge of the next bit, as in Fig. 3, and the result is smooth lumber.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. A saw-tooth having a direct ontting-edge (1, and a lateral cutting-edge 6, meeting the edge (Z at an obtuse angle.

2. A saw-tooth having a directcutting-edge (l substantially at right angles to the plane of the saw, anda draw cutting-edge extending rearWardly and laterally from the direct euttin g-edge, substantially as described.

A saw tooth or bit having a direct cutting-edge, and a draw cutting-edge extending laterally at an angle thereto, substantially as and for the purpose set forth.

In testimony whereof I have hereunto affixed my hand and seal this 5th day of De cember, 1889.

HENRY \V. \VIIEELER. 

